Current use of drains and management of seroma following mastectomy and axillary surgery: results of a United Kingdom national practice survey.

PURPOSE: Up to 40% of the 56,000 women diagnosed with breast cancer each year in the UK undergo mastectomy. Seroma formation following surgery is common, may delay wound healing, and be uncomfortable or delay the start of adjuvant treatment. Multiple strategies to reduce seroma formation include surgical drains, flap fixation and external compression exist but evidence to support best practice is lacking. We aimed to survey UK breast surgeons to determine current practice to inform the feasibility of undertaking a future trial. METHODS: An online survey was developed and circulated to UK breast surgeons via professional and trainee associations and social media to explore current attitudes to drain use and management of post-operative seroma. Simple descriptive statistics were used to summarise the results. RESULTS: The majority of surgeons (82/97, 85%) reported using drains either routinely (38, 39%) or in certain circumstances (44, 45%). Other methods for reducing seroma such as flap fixation were less commonly used. Wide variation was reported in the assessment and management of post-operative seromas. Over half (47/91, 52%) of respondents felt there was some uncertainty about drain use after mastectomy and axillary surgery and two-thirds (59/91, 65%) felt that a trial evaluating the use of drains vs no drains after simple breast cancer surgery was needed. CONCLUSIONS: There is a need for a large-scale UK-based RCT to determine if, when and in whom drains are necessary following mastectomy and axillary surgery. This work will inform the design and conduct of a future trial.

Breast Articles From 2023: Informing Practice Across the Continuum of Care.

With new investigations and clinical trials in breast oncology reported every year, it is critical that surgeons be aware of advances and insights into the evolving care paradigms and treatments available to their patients. This article highlights five publications found to be particularly impactful this past year. These articles report on efforts to select the minimal effective dose of tamoxifen for prevention, to challenge the existing age-based screening guidelines as they relate to race and ethnicity, to refine axillary management treatment standards, to optimize systemic therapy in multidisciplinary care settings, and to reduce the burden of breast cancer-related lymphedema after treatment. Taken together, these efforts have an impact on all facets of the continuum of care from prevention and screening through treatment and survivorship.

Axillary management and long-term oncologic outcomes in breast cancer patients with clinical N1 disease treated with neoadjuvant chemotherapy.

BACKGROUND: Low false negative rates can be achieved with sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) in breast cancer (BC) patients with clinical N1 (cN1) disease. We examined changes in axillary management and oncologic outcomes in BC patients with cN1 disease receiving NAC. METHODS: BC patients with biopsy proven cN1 disease treated with NAC were selected from our institutional cancer registry (2014-2017). Patients were grouped by axillary management, axillary lymph node dissection (ALND), SLNB followed by ALND, or SLNB alone. Univariable and multivariable survival analysis for recurrence-free survival (RFS) and overall survival (OS) were performed. RESULTS: 81 patients met inclusion criteria: 31 (38%) underwent ALND, 25 (31%) SLNB + ALND, and 25 (31%) SLNB alone. A SLN was identified in 45/50 (90%) patients who had SLNB. ALND was performed in 25/50 (50%) patients who had SLNB: 18 for a + SLNB, 5 failed SLNB, and 2 insufficient SLNs. 25 patients had SLNB alone, 17 were SLN- and 8 SLN+. In the SLNB alone group, 23/25 (92%) patients received adjuvant radiation (RT). 20 (25%) patients developed BC recurrence: 14 distant (70%), 3 local (15%), 2 regional + distant (10%), and 1 contralateral (5%). In the SLNB alone group, there was 1 axillary recurrence in a patient with a negative SLNB who did not receive RT. Univariable survival analysis showed significant differences in RFS and OS between axillary management groups, ALND/SLNB + ALND vs. SLNB alone (RFS: p = 0.006, OS: p = 0.021). On multivariable survival analysis, worse RFS and OS were observed in patients with TNBC (RFS: HR 3.77, 95% CI 1.70-11.90, p = 0.023; OS: HR 8.10, 95% CI 1.84-35.60, p = 0.006). CONCLUSIONS: SLNB alone and RT after NAC in BC patients with cN1 disease who have negative SLNs at surgery provides long-term regional disease control. This analysis provides support for the practice of axillary downstaging with NAC and SLNB alone.

Is repeat sentinel lymph node biopsy possible for surgical axillary staging among patients with ipsilateral breast tumor recurrence?

BACKGROUND: There is a lack of studies assessing the survival of repeat sentinel lymph node biopsy (rSLNB) versus axillary lymph node dissection (ALND) for surgical axillary staging among patients with ipsilateral breast tumor recurrence (IBTR). METHODS: We retrospectively identified patients with IBTR from the Surveillance, Epidemiology, and End Results database from 2000 to 2017. The primary outcome was overall survival (OS) between the rSLNB and ALND groups. RESULTS: Of the 2141 women with IBTR after lumpectomy and SLNB, 524 did not receive surgical axillary staging (nonsurgery group) and 1617 patients who did undergo axilla surgery received either rSLNB or ALND as axillary staging (1268 with rSLNB and 349 with ALND). The 10-year OS rates were 61.9% for the nonsurgery and 73.8% for axilla surgery groups (p = .001). In the 1:1 matched cohorts, the 10-year OS rates were 61.4% for the nonsurgery and 69.1% for axilla surgery groups (p = .072). After adjusting for other factors, axillary surgery treatment of IBTR was an independent favorable factor for OS (hazard ratio [HR], 0.71; 95% CI, 0.56-0.90; p = .004). Within the axilla surgery group, rSLNB presented a comparable 10-year OS to the ALND cohort (log-rank test p = .054). Multivariate Cox analysis, as well as subgroup analysis, showed that rSLNB had a similar benefit to ALND (10-year OS; HR, 1.18; 95% CI, 0.88-1.58; p = .268). CONCLUSIONS: The results of this cohort study suggested that receiving surgical axillary staging was associated with better survival of IBTR patients, and rSLNB had a similar long-term survival outcome as ALND. rSLNB might be considered for surgical axillary staging among patients with IBTR after lumpectomy and initial SLNB.

Impact of axillary surgery on outcome of clinically node positive breast cancer treated with neoadjuvant chemotherapy.

PURPOSE: Axillary Lymph Node Dissection (ALND) is recommended for breast cancer patients who present with clinically node positive disease (cN1) especially if they have residual nodal disease (ypN+) following neoadjuvant therapy (NAT). It is unknown whether axillary dissection improves outcome for these patients. METHODS: A prospectively maintained database was used to identify all patients who were diagnosed with cTis-T4N1M0 breast cancer treated with NAT. RESULTS: In our study, of 292 cN1 breast cancer patients who received NAT, we compared ALND with targeted axillary surgery (TAS) in ypN+ patients. ALND was performed in 75% of the ypN+ subgroup, while 25% underwent TAS. Axillary recurrence occurred in four ALND patients, but no recurrence was observed in the TAS group (p = 0.21). Five-year axillary recurrence-free survival was 100% for TAS and 90% for ALND (p = 0.21). Overall survival at five years was 97% for TAS and 85% for ALND (p = 0.39). Disease-free survival rates at five years were 51% for TAS and 61% for ALND (p = 0.9). Clinicopathological variables were similar between the groups, although some differences were noted. ALND patients had smaller clinical tumor size, larger pathological tumor size, more lymph nodes retrieved, larger tumor deposits, higher rates of extranodal extension, and greater prevalence of macrometastatic nodal disease. Tumor subtype and size of lymph node tumor deposit independently predicted survival. CONCLUSION: Axillary recurrence is infrequent in cN1 patients treated with NAT. Our study found that ALND did not reduce the occurrence of axillary recurrence or enhance overall survival. It is currently uncertain which patients benefit from axillary dissection.

Trends in use of neoadjuvant systemic therapy in patients with clinically node-positive breast cancer in Europe: prospective TAXIS study (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

PURPOSE: The aim of this study was to evaluate clinical practice heterogeneity in use of neoadjuvant systemic therapy (NST) for patients with clinically node-positive breast cancer in Europe. METHODS: The study was preplanned in the international multicenter phase-III OPBC-03/TAXIS trial (ClinicalTrials.gov Identifier: NCT03513614) to include the first 500 randomized patients with confirmed nodal disease at the time of surgery. The TAXIS study's pragmatic design allowed both the neoadjuvant and adjuvant setting according to the preferences of the local investigators who were encouraged to register eligible patients consecutively. RESULTS: A total of 500 patients were included at 44 breast centers in six European countries from August 2018 to June 2022, 165 (33%) of whom underwent NST. Median age was 57 years (interquartile range [IQR], 48-69). Most patients were postmenopausal (68.4%) with grade 2 and 3 hormonal receptor-positive and human epidermal growth factor receptor 2-negative breast cancer with a median tumor size of 28 mm (IQR 20-40). The use of NST varied significantly across the countries (p < 0.001). Austria (55.2%) and Switzerland (35.8%) had the highest percentage of patients undergoing NST and Hungary (18.2%) the lowest. The administration of NST increased significantly over the years (OR 1.42; p < 0.001) and more than doubled from 20 to 46.7% between 2018 and 2022. CONCLUSION: Substantial heterogeneity in the use of NST with HR+/HER2-breast cancer exists in Europe. While stringent guidelines are available for its use in triple-negative and HER2+ breast cancer, there is a need for the development of and adherence to well-defined recommendations for HR+/HER2-breast cancer.

Estimating the Benefit of Preoperative Systemic Therapy to Reduce the Extent of Breast Cancer Surgery: Current Standard and Future Directions.

Once reserved for locally advanced tumors which were deemed inoperable at presentation, preoperative systemic therapy (PST) is nowadays increasingly used to treat early breast cancer. PST allows for in vivo assessment of tumor response, for tailoring of adjuvant systemic therapy and for de-escalation of breast and the axillary surgery. Increased rates of pathological complete response together with more accurate response assessment and surgical planning have led to a significant reduction in surgical morbidity. While surgical assessment remains the standard of care, ongoing studies are evaluating whether surgery can be omitted in patients who achieve a complete pathological response. In this chapter, I will review the impact of PST on surgical de-escalation and the data supporting the safety of this approach.

Use of sentinel lymph node biopsy in elderly patients with breast cancer - 10-year experience from a Swiss university hospital.

BACKGROUND: The Choosing Wisely initiative recommended the omission of routine sentinel lymph node biopsy (SLNB) in patients ≥ 70 years of age, with clinically node-negative, early stage, hormone receptor (HR) positive and human epidermal growth factor receptor 2 (Her2) negative breast cancer in August 2016. Here, we assess the adherence to this recommendation in a Swiss university hospital. METHODS: We conducted a retrospective single center cohort study from a prospectively maintained database. Patients ≥ 18 years of age with node-negative breast cancer were treated between 05/2011 and 03/2022. The primary outcome was the percentage of patients in the Choosing Wisely target group who underwent SLNB before and after the initiative went live. Statistical significance was tested using chi-squared test for categorical and Wilcoxon rank-sum tests for continuous variables. RESULTS: In total, 586 patients met the inclusion criteria with a median follow-up of 2.7 years. Of these, 163 were ≥ 70 years of age and 79 were eligible for treatment according to the Choosing Wisely recommendations. There was a trend toward a higher rate of SLNB (92.7% vs. 75.0%, p = 0.07) after the Choosing Wisely recommendations were published. In patients ≥ 70 years with invasive disease, fewer received adjuvant radiotherapy after omission of SLNB (6.2% vs. 64.0%, p < 0.001), without differences concerning adjuvant systemic therapy. Both short-term and long-term complication rates after SLNB were low, without differences between elderly patients and those < 70 years. CONCLUSIONS: Choosing Wisely recommendations did not result in a decreased use of SLNB in the elderly at a Swiss university hospital.

Whole breast radiotherapy in cN0 early breast cancer patients with pathological sentinel lymph nodes (pN1mic, pN1a) without axillary dissection: preliminary results of the observational LISEN trial.

PURPOSE: Axillary management remains unclear when sentinel lymph node (SLN) results are positive in cN0 patients with breast cancer (BC). The trial ACOSOG Z0011 represented a revolution with axillary lymph node dissection (ALND) omission in SLN+ patients, despite critiques regarding non-uniformity of radiation fields. We conducted an observational study (LISEN) where whole breast radiotherapy (WBRT) was planned with tangential fields without nodal irradiation in patients eligible for the Z0011 trial. METHODS: Inclusion criteria were female patients with histologically proven BC, cT1-2cN0, planned conservative surgery, no neoadjuvant therapy. Patients were stratified into two groups: micrometastatic (pN1mic, group 1) and macrometastatic (pN1a, group 2) lymph nodes. Tangential field WBRT was mandatory. Clinical outcomes were analysed, measured from surgery until the first event. RESULTS: In all, 199 patients underwent conservative surgery and SLN biopsy; 133 patients meeting criteria were analysed: 41 patients (30.8%) pN1mic and 92 (69.2%) pN1a. The 5­year disease-free survival (DFS) was 95.0% (85.9-100%) in group 1 and 93.0% (86.3-100.0%) in group 2 (p = 0.78). Overall survival (OS) was 100% (100-100%) in group 1 and 97.4% (92.4-100%) in group 2 (p = 0.74). For the whole cohort DFS and OS were 93.6% (88.2-99.4%) and 96.9% (91.5-100.0%), respectively. For groups 1 and 2, the 5­year outcomes were 5.0% (0.0-14.4%) and 2.3% (0.0-6.1%) for local recurrence (p = 0.51), and 6.2% (0.0-17.4%) and 7.0% (0.0-13.7%) for distant metastasis (p = 0.61), respectively. In group 1, regional recurrence (RR) and local regional recurrence (LRR) were 5.0% (0.0-14.1%; p = 0.13). In group 2, RR and LRR were 0.0% (0.0-0.0%). CONCLUSION: Our results showed good regional control in patients who met the Z0011 trial criteria. WBRT, without nodal surgery or RT, avoiding axillary morbidity, seems to be a good choice.

Nodal positivity decreases with age in women with early-stage, hormone receptor-positive breast cancer.

BACKGROUND: Despite data demonstrating the safety of omitting axillary surgery in older women with early-stage breast cancer, the incidence of axillary surgery remains high. It was hypothesized that the prevalence of nodal positivity would decrease with advancing age. METHODS: The National Cancer Data Base was used to construct a cohort of adult women with early-stage, clinically node-negative, estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative breast cancer treated between 2013 and 2015. Multivariable logistic regression was used to assess the relationship between age and nodal positivity, and this was stratified by the axillary surgery category. Modified Poisson regression was used to estimate the proportion of women receiving adjuvant therapy according to age and nodal status. RESULTS: The incidence of axillary surgery among women aged 70 and older (n = 51,917) remained high nationwide (86%). There was a significant decrease in nodal positivity with advancing age in women with early-stage, ER+, clinically node-negative breast cancer from the youngest cohort up to patients aged 70 to 89 years, and this was independent of histologic subtype (ductal vs lobular), race, comorbidities, and socioeconomic factors. Overall, less than 10% of women aged 70 or older who underwent surgery had node-positive disease, regardless of axillary surgery type, and almost 95% of node-positive patients aged 70 or older were at pathological stage N1mi or N1. CONCLUSIONS: Axillary surgery may be safely omitted for many older women with ER+, clinically node-negative, early-stage breast cancer. Nodal positivity declines with advancing age, and this suggests varied biology in older patients versus younger patients.

Subtype-Guided 18 F-FDG PET/CT in Tailoring Axillary Surgery Among Patients with Node-Positive Breast Cancer Treated with Neoadjuvant Chemotherapy: A Feasibility Study.

BACKGROUND: The purpose of this study was to investigate the value of 18 [F]-fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) in tailoring axillary surgery by predicting nodal response among patients with node-positive breast cancer after neoadjuvant chemotherapy (NAC). METHODS: One hundred thirty-three patients with breast cancer with biopsy-confirmed nodal metastasis were prospectively enrolled. 18 F-FDG PET/CT scan was performed before NAC (a second one after two cycles with baseline maximum standardized uptake value [SUVmax ] ≥2.5), and a subset of patients underwent targeted axillary dissection (TAD). All the patients underwent axillary lymph node dissection (ALND). The accuracy was calculated by a comparison with the final pathologic results. RESULTS: With the cutoff value of 2.5 for baseline SUVmax and 78.4% for change in SUVmax , sequential 18 F-FDG PET/CT scans demonstrated a sensitivity of 79.0% and specificity of 71.4% in predicting axillary pathologic complete response with an area under curve (AUC) of 0.75 (95% confidence interval, 0.65-0.84). Explorative subgroup analyses indicated little value for estrogen receptor (ER)-negative, human epidermal growth factor receptor 2 (HER2)-positive patients (AUC, 0.55; sensitivity, 56.5%; specificity, 50.0%). Application of 18 F-FDG PET/CT could spare 19 patients from supplementary ALNDs and reduce one of three false-negative cases in TAD among the remaining patients without ER-negative/HER2-positive subtype. CONCLUSION: Application of the subtype-guided 18 F-FDG PET/CT could accurately predict nodal response and aid in tailoring axillary surgery among patients with node-positive breast cancer after NAC, which includes identifying candidates appropriate for TAD or directly proceeding to ALND. This approach might help to avoid false-negative events in TAD. IMPLICATIONS FOR PRACTICE: This feasibility study showed that 18 [F]-fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) could accurately predict nodal response after neoadjuvant chemotherapy (NAC) among patients with breast cancer with initial nodal metastasis except in estrogen receptor-negative, human epidermal growth factor receptor 2-positive subtype. Furthermore, the incorporation of 18 F-FDG PET/CT can tailor subsequent axillary surgery by identifying patients with residual nodal disease, thus sparing those patients supplementary axillary lymph node dissection. Finally, we have proposed a possibly feasible flowchart involving 18 F-FDG PET/CT that might be applied in post-NAC axillary evaluation.

Disparities in the Use of Sentinel Lymph Node Dissection for Early Stage Breast Cancer.

BACKGROUND: Clinical trials have long established the long-term safety of omitting axillary lymph node dissection (ALND) after sentinel lymph node dissection (SLND) in patients with clinically node-negative early stage breast cancer. The variations in utilization of SLND and ALND in this patient population, however, are currently unknown. METHODS: Adult female patients (40 years and older) within the National Cancer Database diagnosed with breast cancer between January 2013 and December 2015, who had clinical T1-T2 and N0 disease, and who underwent either SLND (with or without subsequent ALND) or ALND were included. Differences in utilization across race, ethnicity, insurance type, facility, and residential characteristics were assessed using multivariable logistic regression. RESULTS: Overall, 271,689 patients were included, of which 26,527 (10%) received ALND and 245,162 (90%) underwent SLND. After adjusting for demographics and cancer characteristics, black (odds ratio [OR], 1.11; 95% confidence interval [95% CI], 1.06-1.17) and Hispanic women (OR, 1.16; 95% CI, 1.10-1.24) were more likely to receive ALND. Patients without health insurance (OR, 1.33; 95% CI, 1.19-1.47), compared with private health insurance, and those receiving treatment at community cancer centers (OR, 1.60; 95% CI, 1.53-1.67), compared with academic/research centers, were also more likely to receive ALND. CONCLUSIONS: Although the vast majority of women undergo SLND, significant disparities exist in its utilization for early stage breast cancer, with traditionally underserved patients receiving unwarranted extensive axillary surgery. Increased patient and surgeon education is needed to decrease variations in care that can affect patient's quality of life.

Primary tumor resection in de novo stage IV breast cancer patients.

Breast and axillary surgery in Stage IV disease is outside current national guidelines but has been a topic of ongoing debate. A single institution retrospective study identified women with de novo stage IV BC from 2011-2016 to evaluate the rate and goals of primary site surgery. Only 10.2% (n = 27/265patients) had primary site surgery. The goal of surgery was most often treatment intent (n = 23, 85.1%) not palliation (n = 4, 14.8%). There was no 30-day mortality and low (n = 1, 3.7%) 30-day morbidity. Multi-disciplinary patient care pathways based on modern evidence may help identify patients potentially suitable for primary site surgery.

Sentinel and non-sentinel lymph node metastases in patients with microinvasive breast cancer: a nationwide study.

PURPOSE: To determine the incidence and risk factors of sentinel lymph node (SN) and non-SN metastases in patients with microinvasive breast cancer (MIBC, T1mic). This to identify MIBC patients in whom axillary staging can be safely omitted. METHODS: The Danish Breast Cancer Group database was used to identify a total of 409 women with breast cancer ≤ 1 mm who underwent sentinel lymph node biopsy (SLNB) between 2002 and 2015. After validation, 233 patients were eligible for the analysis. The incidence rates of SN and non-SN metastases were determined. The associations between clinicopathological variables and a positive SN [pN1, pN1mi, or pN0(i+)] were analyzed using univariate and multivariate designs. RESULTS: Of 233 patients with MIBC, only 9 (3.9%) had SN macrometastases. An additional 18 (7.7%) and 23 (9.9%) had SN micrometastases and isolated tumor cells (ITCs), respectively. Of patients with SN macrometastases, two (22.2%) had non-SN macrometastases. In the adjusted analysis, a positive SN was associated with younger age (P = 0.0001) and a positive human epidermal growth factor 2 receptor (HER2) status (P = 0.03). CONCLUSIONS: The low incidence of SN macrometastases < 4% suggests omission of axillary staging in MIBC patients without staging at primary surgery, especially in older (≥ 50 years) HER2- patients. Still, the relatively high proportion of patients with non-SN macrometastases indicates that axillary treatment might be considered in SN positive patients, especially in younger HER2+ MIBC patients.

Breast cancer subtypes affect the nodal response after neoadjuvant chemotherapy in locally advanced breast cancer: Are we ready to endorse axillary conservation?

We evaluated the impact of breast cancer subtypes on pathologic complete response (pCR) in 181 patients with positive nodes undergoing neoadjuvant chemotherapy (NAC). After NAC, patients underwent surgery, with sentinel lymph node biopsy (SLNB) or axillary dissection (ALND). In 28.2% of cases a pCR was achieved, with the highest rate in Her2+ and triple negative tumors. Overall, nodal pCR was more frequent than breast pCR (P = 0.003) with higher percentages in Her2+ and LLB-Her2+ (P < 0.05). In the Her2+ group, nodal pCR was observed only with breast pCR. Thus, in Her2+ tumors, breast pCR predicts node pCR, supporting the use of SLNB in this subgroup to stage the axilla avoiding ALND.

Patterns of axillary evaluation in older patients with breast cancer and associations with adjuvant therapy receipt.

PURPOSE: Although axillary lymph node status has traditionally been a key factor in informing adjuvant breast cancer therapy recommendations, this information may be less relevant as our focus shifts more towards tumor biology, particularly in older patients where comorbidity influences treatment decisions and nodal staging and/or surgery may not improve outcomes. We examined patterns of axillary surgery and associations between axillary surgery and receipt of adjuvant treatment in older breast cancer patients. METHODS: Women aged ≥ 65 years with clinically node-negative, stage I-II breast cancer treated between 2012 and 2013 were identified using the National Cancer Data Base. Using multivariable logistic regression, we examined associations between axillary surgery and age, adjusting for patient, clinical, and facility factors. We also examined receipt of adjuvant treatment by nodal surgery. RESULTS: Among 68,205 women, 40.1% were aged 65-70, 24.5% were 71-75, 17.4% were 76-80, and 18.0% were > 80. Overall, 91.2% had axillary surgery (67.8% sentinel lymph node biopsy, 11.7% axillary lymph node dissection, 11.7% unspecified/unknown axillary surgery); 88.0% of those aged ≥ 70 with lower risk, hormone receptor-positive tumors underwent axillary surgery. In adjusted analyses, compared to patients aged 65-70, increasing age was associated with lower odds of any axillary surgery (ages 71-75: OR 0.64, 95% CI 0.57-0.71; ages 76-80: OR 0.33, 95% CI 0.30-0.37; age > 80: OR 0.08, 95% CI 0.07-0.08). Axillary surgery was associated with higher odds of receipt of radiation after breast conservation and receipt of chemotherapy in human epidermal growth factor 2-positive disease. CONCLUSIONS: In a large nationwide dataset, the vast majority of older women with clinically node-negative breast cancer underwent axillary staging despite uncertainty about its impact on survival, particularly for those with lower-risk disease. Further study on how to tailor node assessment in older patients is warranted.

Extent of regional lymph node surgery and impact on outcomes in patients with early-stage breast cancer and limited axillary disease undergoing mastectomy.

PURPOSE: Management of the axilla in patients with early-stage breast cancer (ESBC) has evolved. Recent trials support less extensive axillary surgery in patients undergoing mastectomy. We examine factors affecting regional lymph node (RLN) surgery and outcomes in patients with ESBC undergoing mastectomy. METHODS: Women with clinical T1/2 N0 M0 invasive BC who underwent mastectomy with 1-2 positive nodes were selected from the National Cancer Database (2004-2015). Axillary surgery was defined by number of RLNs examined: 1-5 sentinel LN dissection (SLND), and ≥ 10 axillary LND (ALND). Binary logistic regression and survival analyses were performed to assess the association between axillary surgery and clinical characteristics, and overall survival (OS), respectively. RESULTS: 34,243 patients were included: 13,821 SLND (40%) and 20,422 ALND (60%). SLND significantly increased from 21% (2004) to 45% (2015) (p < .001). Independent factors associated with SLND were treatment year, non-Academic centers, geographic region, tumor histology, and postmastectomy radiotherapy (PMRT). Multivariable survival analysis showed that ALND was associated with better OS (HR 0.78, 95% CI 0.72-0.83, p < .001) relative to SLND; however, there was no difference in patients with LN micrometastases treated without RT (HR 0.87, 95% CI 0.73-1.05, p = .153) or patients receiving PMRT (HR 0.92, 95% CI 0.76-1.13, p = .433). CONCLUSIONS: SLND has significantly increased in patients undergoing mastectomy with limited axillary disease and is influenced by patient, tumor, and treatment factors. Survival outcomes did not differ by axillary treatment for patients with LN micrometastases treated without RT or patients who received PMRT. SLND may be considered in select patients with ESBC and limited axillary disease undergoing mastectomy.

Management of the axilla after neo-adjuvant chemotherapy for breast cancer: Sentinel node biopsy and radiotherapy considerations.

Preoperative or neo-adjuvant chemotherapy in the management of breast cancer is a treatment approach that has gained in popularity in recent years. However, it is unclear if the treatment paradigms often employed for patients treated with surgery first hold true for those treated with preoperative chemotherapy. The role of sentinel node biopsy and the data supporting its use is different for those with clinically negative and clinically positive nodes prior to chemotherapy. For clinically node-negative patients, sentinel node biopsy after neo-adjuvant chemotherapy may be appropriate. For those node-positive patients whose axillary disease resolves clinically, the false-negative rate of the sentinel node biopsy is high. However, there are measures that can reduce that rate. After surgery, the radiation oncologist is often faced with complicated decisions surrounding the optimal radiotherapy in this setting. Tailoring radiation plans based on chemotherapy response holds promise and is the subject of ongoing clinical trials. In the accompanying article, we review the current literature on both surgery and radiation in axillary management and describe the interplay between these two treatment modalities. This highlights the need for multidisciplinary management in making treatment decisions for patients treated in this manner.

The impact of preoperative axillary ultrasonography in T1 breast tumours.

OBJECTIVES: To (a) determine the diagnostic validity of axillary ultrasound (AUS) in pT1 tumours and whether fine-needle aspiration (FNA) improves its diagnostic performance, and (b) determine the negative predictive value (NPV) of AUS in a simulation environment (cutoff: two lymph nodes with macrometastases) in patients fulfilling American College of Surgeons Oncology Group (ACOSOG) Z0011 criteria. MATERIALS AND METHODS: This retrospective multicentre cross-sectional study analysed diagnostic accuracy in 355 pT1 breast cancers. All patients underwent AUS; visible nodes underwent FNA regardless of their AUS appearance. Sentinel node biopsy and axillary lymph node dissection (ALND) were gold standards. Data were analysed considering micrometastases 'positive' and considering micrometastases 'N negative'. The simulation environment included all patients fulfilling ACOSOG Z0011 criteria. RESULTS: Axillary involvement: 22.8 %; AUS sensitivity: 46.9 % (Nmic positive)/66.7 % (Nmic negative); AUS+FNA sensitivity: 52.6 % (pNmic positive)/72.0 % (pNmic negative). In the simulation environment, AUS had 75.0 % sensitivity, 88.9 % specificity and 99.2 % NPV. CONCLUSION: AUS has moderate sensitivity in T1 tumours. As ALND is unnecessary in micrometastases, considering micrometastases 'N negative' increases the practical impact of AUS. In patients fulfilling ACOSOG Z0011 criteria, AUS alone can predict cases unlikely to benefit from ALND. KEY POINTS: • AUS+FNA can predict axillary involvement, thus avoiding SNB. • Not all patients with axillary involvement need ALND. • Axillary tumour load determines axillary management. • AUS could classify patients according to axillary load.